Upgrades is a single powerup that can be used to power up the ability of a bird or pig currently on the slingshot. Upgrades are:
- Red Bird > Shaker Bird: shakes the fortress with its scream. When it screams, it breaks all glass
- Blue Bird > Five-splitter Bird: splits into five slightly smaller but powerful birds that can break wood
- Yellow Bird > Light Bird: speeds up incredibly faster, doesn't lose its speed when activated. Can break ice
- Black Bird > TNT Bird: a bit lighter, and explodes directly on impact and when activated
- White Bird > Three Egg Bird: can activate ability three times until flattened or already became corpse
- Boomerang Bird > Back Bird: when activated, goes back and shakes the fortress at the same time.
- Big Brother Bird > Big Shaker Bird: more shaking, and its moan breaks wood
- Orange Bird > Balloon Bird: when deflating, blows away everything nearby.
- Ice Bird > Blizzard Bird: a bigger explosion and bigger freezing radius.
- Pink Bird > Bubblewand Bird: slightly bigger, and blows 10 more bubbles and can repeat the bubble blowing 10 times